TRADE unionists called on Scotland Yard today to come clean about the full extent of the police role in the blacklisting of thousands of construction workers and environmentalists.

Leigh Day solicitors, on behalf of the GMB, have filed a Freedom of Information request demanding the Metropolitan Police’s full report about the role of the police force in blacklisting.

The firm is also demanding the release of emails and details of meetings between police officers and blacklisting firms, following revelations that coppers and special branch officers spied on trade unionists and passed on information.

Bosses kept secret files on more than 3,200 people working in construction, which the GMB describes as the “greatest employment scandal” of the past 50 years.

The union's national officer Justin Bowden demanded that the full information see the light of day.

“Workers and environmentalists deserve to know exactly what role the police played in supplying information about them to the construction companies," he said.

“They have a right to know who, what, where, when and why information was shared between the police and the construction companies.

“There is a clear public interest in this information being provided.

“It is now time for Scotland Yard to make public everything that they did and come clean about their part.”

Scotland Yard has stated that police involvement with blacklisting will be “fully explored” in the ongoing public inquiry into undercover policing.

The scandal emerged in 2009 when the Information Commissioner’s Office seized a database from an organisation called the Consulting Association.

A list containing 3,213 names of construction workers and environmentalists was discovered on the database.

Forty-four corporations and companies were also found to have been using the database when vetting new recruitments, including Carillion, Balfour Beatty, Laing O’Rourke and Sir Robert McAlpine.